Electromagnetic brake



Nov. 20, 1923 BA'MBGQ B. E. FERNOW JR ELECTROMAGNETIC BRAKE Fi led Ju on y 2, 1-921 IIIilEL IN VEN TOR.

ATTORNEY lltl Patented Novi 2d, 1223.

ld hlllfli'ldifi BERNHARD E. FERNOW, 33., OF MILWAUKEE, WISCONSIN, ASSIGNOR TO THE CUTLER- HAEMER MFG. CO., MILWAUKEE, WISCONSIN, A CORPORATION OF WISCONSIN.

- ELECTROMAGNETIC RAKE.

Application inedrui 2 ,1e2 1. Serial No. 482,071.

To all whom it may concern:

Be it known that l, BERNHARD E. FEnNoW, Jr., a citizen of the United States,-residing at Milwaukee in the county of Milwaukee and State of Wisconsin, have invented new and useful Improvements in Electromagnetic Brakes, of which the following is a full, clear, concise, and exactdescription, reference being had to the accompanying drawing, forming a part of this specification.

This invention relates to improvements in electro-magnetic brakes. U

The invention is particularly applicable to brakes of-the character disclosed in my Patent No. 1,410,395 of March 21, 1922, and relates more particularly to means for equalizing the releasing movements of the shoes of such brakes.

The brake disclosed in said application is desi ed for mounting in a position wherein the ld and armature members of the magnet tend to move away from the drum under the influence of gravity and the same is provided with an adjustable stop for effecting equalization of the releasing movements of the brake levers when the brake is so mounted. However, if the brake is mounted in a position wherein the armature and field members tend to move towards the drum underthe influence of gravity such stop will permit the shoe associated with the armature member to remain in engagement with the drum, and the present invention hasamong its objects to provide means for equalizing the releasing movements of the shoes when the brake is so mounted.

Another object is to provide means of the aforesaid character which can be readily applied to the brake without materially altering the construction of the parts thereof.

Various other objects and advantages of the invention will hereinafter appear.

The accompanying drawing illustrates certain embodiments of the invention and the same will now be described, it being understood that the embodiments illustrated are susceptible of various modifications without departing from the scope of the appended c aims.

lin the drawing, I a

Fig. 1 is a side elevational view of a brake embodying the invention, the electromagnet being shown partially in section;

Fig. 2 is a top plan view of Fig. 1; and 1 Fig. 3 is a side elevational view of a brake embodying the invention in a modified form.

Referring to thedrawing the same illus trates a brake drum 1 to be secured to the motor or other device to be braked, opposed brake shoes 2 and 3 to frictionally engagesald drum and levers 4 and 5 supporting said shoes respectively. lhe levers 4 and 5 have pivots 6' and 7 respectively on a base 8 and shoes 2 and 3 have pivots 9 and 10 respectively on saidlevers in line with the center of the drum, said levers being provided with adjustable stops 11 and 12 respectively for the lower ends of said shoes.

The lever 5 is provided with a circular portion 13 to be attracted by. an annular field member 14:, said field member bein provided with an annular winding 15 and eingpivotally supported by lugs 16 and Hon the ivot pin of lever 5. Lever 5 and field mom or 14 are biased apart by a spring '18 and the free end of lever 1 is connected to the free extremity of said field member by a link connection 19. Spring 18- accordingly serves to set the brake shoes 2 and 3 against drum 1 and energization of winding 15 serves to attract lever 5 and field member 14: towards each other for spreading of said shoes. 1

However, if the brake is mounted as shown in Fig. 1, that is, with the parts of the magnot located above drum 1, it is apparent that upon energization of the magnet, field member 14 and lever 5 will tend to move downwardly under the influence of gravity. Un

less downward'movement of said field memher is limited, shoe 3 will be held in engagement with drum 1 by the weight of the magnet parts while shoe 2 will move away from drum 1 to a degree corresponding to the total movement of said field member.-

For equalizing the releasing movements of shoes 2 and 3 field member. 14 has an ad'- justable stop-2O associated therewith, said. stop being carried by an arm 21 secured to lug 16 of field member 14 and being arranged'to engage a projecting lug 22 on base 8. Stop 20 is normally out of engagement with lug 22 and 'thesame is set to arrest field member 14 in a position wherein lever 5 will be attracted upwardly to a degree substantially equal to the degree of downward movement of said field member; Since the relative movement of shoes 2 and 3 is subthe entire weight offield member 14 when limiting movement thereof towards drum 1. As shown in 'Fig. 3, base 8 is provided sto ber towards said drum, said stop insuring with a projecting lug 23 at one end thereof, said lug being provided with an adjustable 24 for engaging brake lever 4. Stop 24 is adjusted to permit the desired releasing movement of brake lever 4 and the same acts through said lever and the connection 19 to limit movement of the field member 14 towards drum 1. In other words, stop 24 performs the same function as the stop described in connection with Fig. 1.

What I claim as new and desire to secure by Letters Patent is:

1. The combination with a brake drum and opposed brake shoes therefor of an electromagnet having field and armature members, said members being movable in-- dependently of each other and upon brake 1 release tendin to move towards said drum under the in uence of gravity and means associated with one of said members to' limit movement thereof towards said drum, said means being adjustable to fprovide substantially ual movements 0 said brake shoes by sai electromagnet.

2. The combination with a brake drum and opposed brake shoes therefor, of an electromagnet having relatively movable ivoted parts each connected to one of sai brake shoes, said parts upon brake release tending to move towards said drum under the influence of ravity and a stop associated with one of sai; magnet parts for limiting movement thereof towards said drum, said stop insurin substantially equal movements of said bra e shoes by said electromagnet.

3. The combination with a brake drum and opposed brake shoes therefor, of a supporting base, an electromagnet having relatively movable field and armature members pivotally secured to said base, said members upon brake release tendin to move towards said drum under the in uence of gravity and each being connected to one of said shoes and a stop co-operating with said base for limiting movement of said field memsubstantially equal movements of said brake shoes by said electromagnet.

4. The combination with a brake drum and opposed brake shoes therefor, one of the same having a supporting lever of an electromagnet having p1voted armature and drum with its axis substantially field members, said members tending to move towards said drum under the influence of gravity and the former being directly connected to one of said brake shoes and the latter having a link connection with said lever and a stop associated with said field member for limiting movement thereof towards said drum during brake release, said stop insuring substantially equal movements of saidbrake shoes by said electroma net. 5. The combination with a brake um and opposed brake shoes therefor, one of said shoes having a supporting lever of an electromagnet having concentrically pivoted armature and field members tending to move towards said drum under the influence of gravity, one of said members supporting another of said brake shoes and having a stop associated therewith for limiting movement thereof towards said drum and the other of saidmembers having a connection with said lever and a s ring associated with said armature and iield members to spread the same said stop functioning to insure substantlally e ual movements of said brake shoes by sai electromagnet. 6. In a. brake, the combination with a brake drum and opposed brake shoes therefor, of a supporting lever for one of said shoes, an electromagnet arranged adjacent the periphery of said brake drum and rovided with armature and field mem rs tending upon brake release to move towards said drum, one. of said members being opatin means for said brake shoes including an e ectromagnet and operative connections between said brake shoes and relatively movable parts of said electromagnet, said electromagnet being mounted above said erpendicular to the axis of said drum an a stop associated with one of said magnet parts for limiting movement thereof towards said drum said stop beingv adjustable to provide substantially equal movements of said brake shoes by said electromagnet.

8. The combination with a brake drum and opposed brake shoes therefor, of actuating means for said brake shoes including an electromagnet having a pivotedarmature member supporting one of said brake shoes, said electromagnet tending to move towards said drum under the influence of gravity and a stop associated with oneof said magnet parts for limiting movement thereof towards said drum, said stop affording substantially equal movements of said brake shoes by said electromagnet.

9. The combination with a brake drum and opposed brake shoes therefor of actuating means for said brake shoes including an electromagnet having concentrically pivoted armature and field members each of said members being connected to one of said brake shoes and tending to move towards said drum under the influence of gravity and a sto associated with one of said members for limiting movement thereof towards I said drum, said sto afi'ording substantially equal movements 0 said brake shoes by said electromagnet.

In witness whereof, I have hereunto sub scribed my name.

BERNHARD E. FERNUW, dis. 

